| 摘要: | 蘇門答臘地區以其可怕的地震歷史而聞名，最具代表性的是2004年的極強地震，該地震為邊緣俯衝所引起。事實上，蘇門答臘斷層系統（SFS）的活動也威脅著該地區，具有巨大的潛在危險。本研究采用一種先進的方法來評估概率性地震危害。為了更好地展示每個地震源可能的地震活動，我們的分析融合了截斷指數模型、長期概率模型（基於時間相關的布朗行程時間（BPT）模型）以及考慮蘇門答臘海溝和蘇門答臘斷層沿多段斷裂的地震速率。由於缺乏地動模型，因此使用地震情景來選擇適當的地動預測方程，分別用於淺成壓實層、邊緣俯衝和俯冲地震帶。為了了解地震源對某些目標地點的影響，展示了震級-距離組合的危險度貢獻。結果表明，SFS是該地區整體地震危險的主要貢獻者，在蘇門答臘的基岩站點上，短期和長期回歸期的峰值地面加速度(PGA) 值均很高，例如50年內超過10%和2%的概率分別為1.0-1.8 g和3.8-4.0 g。此外，在Sa 0.2 s譜段的地圖上，顯示出在蘇門答臘斷層附近有較高的譜加速度值，其回歸期為475年和2745年時，分別為1.0-1.8 g和3.8-4.0 g，而Sa 1.0 s時的值較低，分別為0.6-0.8 g和1.2-1.8 g。在本論文提出的危險度圖中，我們評估了基岩工程（Vs30=760 m/s) 和場地效應（Vs30 by USGS）。場址效應對於蘇門達臘平原和蘇門達臘斷層周圍的特定區域有影響。此研究的結果可以為應急響應規劃、城市發展和政府機構在蘇門達臘地區發生災難性地震前的準備提供有價值的信息。;The Sumatra region is known for its history of devastating earthquakes, with the most significant being the 20046 {\ M}_w9.2 Aceh earthquake that occurred at subduction interface. In fact, not only the great potential from the source of the megathrust but also the threat due to the activities of the Sumatran fault system (SFS). A progressive approach for assessing the probabilistic seismic hazard is used in this study. In order to better illustrate possible seismic activity of each seismogenic source, our analysis incorporates the truncated exponential model, the long-term probability modelling with time-dependent Brownian Passage Time (BPT) model, and the earthquake rates considering complex multiple-segments rupture along the Sunda Trench and the Sumatran fault. To overcome the lack of ground-motion models, earthquake scenarios were used to choose the appropriate ground motion models for shallow crustal, subduction interface, and subduction intraslab regions, respectively. To understand the impact of seismic sources to some target sites, demonstrate the hazard contributions of magnitude-distance sets through disaggregation. The results indicate that the SFS is the primary contribution to the overall seismic hazard in the region, with peak ground acceleration (PGA) values at bedrock sites of Sumatra in both short and long return periods, e.g., 10% and 2% probability of exceedance in 50 years, respectively. Besides, the maps for spectral periods shows high spectral acceleration values levels in the vicinity of Sumatran fault at Sa 0.2 s with return periods of 475 years and 2745 years are 1.0-1.8 g and 3.8-4.0 g, while the Sa 1.0 s had lower values of 0.6-0.8 g and 1.2-1.8 g for longer periods of time, respectively. In our the hazard maps proposed in this thesis, we evaluated the bedrock engineering (Vs30 =760 m/s) and sSite effects (Vs30 by USGS). SSite effects has an impact on the Sumatran plain and specific areas around the Sumatran fault. The outcomes of this study can provide valuable information for emergency response planning, urban development, and preparedness of governmental agencies before a disastrous earthquake in the Sumatra region. |
